Slasher sizing composition and yarns sized therewith



Patented Nov. 19, 1946 SLASHER SIZING COMPOSITION YARNS SIZED THEREWITH Vernal Richard Hardy, Wilmington, and Walter Richard Haefele, Bridgeville, Del., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application May 27. 1943, Serial No. 488,774

Claims. 1

This invention relates to a sizing composition, and more particularly to a sizing composition suitable for the slasher sizing of nylon yarn.

It is customary to size yarns for weaving and it is common to size the yarn on a slasher or to use so-called single-end sizing methods. The slasher sizing method is more economical and, in addition, contributes to good fabric quality by evening out warp ends with respect to shrinkage properties, dyeing, and the like. In the slasher sizing method, several ends of yarn (frequently several thousand ends of yarn) are led through a sizing bath, then through squeeze rolls, around drying cans to splitting rods, and then to a. takeup device. The yarns run very close to each other in the conventional equipment and they tend to touch, even to intertwine. It is common to see two or three ends go over the drying cans as a superficially adhered bundle and, when this bundle reaches the splitting rods, the yarns become separated and they are wound onto beams as an orderly fleece of ends.

The weaving of nylon yarn has, up to thepresent time, required single-end sizing technique since no operative slasher sizing technique could be developed. Nylon is a very smooth, slick yarn with a low water-sensitivity. It is difilcult to develop sizing compositions which will adhere to the yarn sufiiciently to afford proper protection and which will go through the loom without dusting or flaking ofi on the delicate working parts of the loom. Using excellent slasher sizing and weaving techniques but using the available nylon sizes that were developed for single-end sizing, it is common to have numerous end brakes (one for every one-half yard of iabric woven).

It is an object of this invention to provide an adequate slasher sizing composition for nylon yarn.

Another object of this invention is to provide a slasher size for nylon which is weak enough so that the ends will separate at the splitting rods but strong enough to holdthe filaments in a bundle including .broken filaments which will wrap around adjacent ends.

The objects are attained, in general, by a sizing composition consisting essentially 01 polyvinyl alcohol in combination with an alkylol ureaformaldehyde resin, as will be more fully explained hereinafter.

The invention is based on the observation that nylon yarns behave in a loom in a unique mannor, as distinguished from other yarns, and this behavior seems to be related to the high tenacity and elasticity of the nylon yarns. For example,

by careful inspection, it was observed that when a filament broke in going through the loom,'it snapped and wound itself tightly around an adjacent yarn and it finally broke that yarn end and stopped the loom. This is a situation which is not serious with any other yarn. This: seems to suggest a sizing composition of such film strength that, should the filament break, it is prevented irom wrapping, or, if it does wrap, the filament is more easily broken than the adjacent yarn. Sizing compositions of very strong film strength were, however, not satisfactory for the reason that, when two ends superficially adhered together in .the slashing treatment came to the splitting rods, the film of sizing composition resisted rupture and a yarn end had to break to clear thesplitting rods. A 'problem was posed then of developing a sizing composition to operate within these opposing limits of end breaks on the slasher and end breaks on the loom.

In order that the invention may be quite clear, there is hereinafter set forth a specific example.

Example A size solution was prepared comprising equal parts of partially saponified polyvinyl acetate having a saponification number of and a viscosity of 4 centipoises and of the water-soluble condensation product of N -ethanol urea and formaldehyde in 'water to give 11.5% solids. The alkylol urea-formaldehyde resin is prepared by the process set forth in Example I of U. S. Patent 2,331,926 and is the water-soluble condensation product of N-beta hydroxyethyl urea with formaldehyde, sold by the Sharples Chemicals, Inc. and known as Aquarea Resin No. 4184B. 4596 ends of 40/13/5 hexamethylene adipamide polymer yarn were run through the size bath at room temperature on a slashing machine. The yarn ends were then run through a conventional squeeze roll and onto five drying cans maintained at 220 F. The rate of travel of the yarn through the bath and the pressure of the squeeze rolls were adjusted to provide a size coating of 6.5% on the yarn. The dried yarn ends ran through the splitting rods and were wound up on a beam.

The yarn ends, though sometimes superficially intertwined for a short distance along their length, were easily, separated at the splitting rods with substantially no end breaks and the beamed yarn operated very smoothly in the loom. There was practically no flaking as would be noted by deposit on the loom parts. It was a common experience to weave 25 yards without an end break.

the bath, the pressure of the squeeze rolls, and

the amount of size desired on theyyarn. It will The size is readily removable in an aqueous boilbe obvious, too, that the amount of size on the yarn depends on such variables as discussed above. Good results have been secured with quantities of between 2% and 9% on the yarn.

In the foregoing example, preference has been shown for a specific polyvinyl acetate and a specific condensation product of an allqylol urea and formaldehyde. The invention, however,

broadly contemplates the preparation of slasher importance of this invention resides in the development of the flrsteifective slasher sizing composition for nylon. It will be evident to those skilled in the art that the general principles of this invention may be practiced with other watersoluble resins having comparable properties.

The optimum proportions of the polyvinyl alcohol and the resin are 50:50, but the invention works well within the limits of 25:75 and 75:25.

The invention has been discussed in terms of nylon yarns, and more specifically the polyhexamethylene adipamide yarn since that is the common nylon yarn on the market.

The principles of the invention are equally applicable to any other very strong, quite elastic, water-insensisizes from polyvinyl alcohol and derivatives of polyvinyl alcohol together with condensation products of alkylol ureas and formaldehyde. Since one of the prerequisites for a satisfactory size is the ready removal thereof in an aqueous boil-off bath, the components of the size are readily removable inan-aqueous boil-oil bath. Generally speaking, any water-sensitive polyvinyl compound in which 1% to 50%, and preferably 20% to 50%, of the carbon atoms in the polyvinyl chain are attached to hydroxyl groups (such compounds being hereinafter referred to as hydroxylated polyvinyl resin) can be used. As illustrative examples of hydroxylated polyvinyl resins which can be used are the partial esters of polyvinyl alcohol such as the partial acetates,

I the partial propionates, the glycolic acid esters,

the partial formate's, and the partial lactates; the partial ethers of polyvinyl alcohol such as the glycol ethers, the glycolic acid ethers, the methyl ethers, and the ethyl ethers; the partial acetals of polyvinyl alcohol such as the partial formal, the partial acetal, the partial'glyoxal, the partial propional, and the partial butyral; the partial ketals of polyvinyl alcohol such as the ethylmethyl ketal.

Although partially saponified polyvinyl acetates having saponification numbers from 135 to 145 are particularly useful, partially saponified polyvinyl acetates having saponification numbers of between 10 and 300, such as 40 to 200, or even somewhat lower than 10 or higher than 300, may be used to advantage. saponification numbers of the partially saponified polyvinyl acetate, as used herein, are defined as the number of milligrams *of potassium hydroxide required to completely saponify one gram of the sample.

The partially saponified polyvinyl acetate may have viscosities of 1.5 to 20 centipoises, and preferably 4 to 6 centipoises, the viscosity being detive yarn, among which may. be mentioned many of the linear polymer and in'terpolymer yarns disclosed in U. S. Patents Nos. 2,071,250, 2,150,523 and 2,130,948 as derived from polymerizable monoaminocarboxylic acids or their amide-forming derivatives and those derived from the reaction of suitable diamines with suitable dicarboxylic acids or amide-forming derivatives of dibasic carboxylic acids. In addition, there may be mentioned yarns made from acrylonitrile polymers, vinyl chloride-vinyl acetate copolymers, vinylidene chloride polymers, polyvinyl chloride, chlorinated polyvinyl chloride, ethylene polymers, and methyl methacrylatepolymers.

As is indicated, the invention has particular concern for a sizing composition which can well be employed for-slasher sizing. It is true that the sizing composition is also good forsingle-end sizing for weaving. It was unexpected that this sizing composition, which was so useful for weaving, would, when modified in the conventional way with boric acid, also be useful for knitting, since nylon yarns for weaving promises to be a comtermined on a4% aqueous solution at 20 C. us-

soluble condensation product of N-beta hydroxyethel urea with formaldehyde (Sharples Chemical's, Inc. Aquarea Resin No. 4184B). other water-soluble resins obtained by the condensation of alkylol urea and formaldehyde or other water-soluble resins having properties comparable to that herein used may beemployed. The

mercial reality. Fortunately, it involves no "alterations in existing equipment or technique except for the use of the sizing composition. The industry, remembering the early difliculties in the weaving of slashed nylon warps, is much gratified at the smoothness of operation which these sizes offer. It might be mentioned in passing that the loom efiiciencies in 'weaving nylon are 'definitely higher than were obtained with any other slasher size and approach those obtained with other yarns.

Since it is obvious that many changes and modifications can be made in the above-described details without departing from the nature-and spirit of the invention, it is to be understood that the invention is not to be limited to the details described herein except as set forth in the appended claims.

We claim:

1. Aslasher sizing composition for water-insensitive yarns composed of a linear polyamide comprising the reaction product of a linear polymerforming composition which comprises in substantial amountreactingmaterial selected from at least one of the groups consisting of (a) monoaminomonocarboxylic acids and (b) mixtures of diamine with dibasic carboxylic acid, said sizing composition comprising a hydroxylated polyvinyl resin and a water-soluble condensation product of N-beta hydroxyethyl urea with formaldehyde, the proportions of the hydroxylated polyvinyl resin and the condensation product being within v the limitsof 25:25 and :25, Bald p lyvinyl resin I polyvinyl chain attached to hydroxyl groups, the

size resulting from said composition being readily removable in an aqueous boil-off bath.

2'. A sizing composition for water-insensitive yarns comprising a partially saponified polyvinyl acetate and a water-soluble condensation product of N-beta hydroxyethyl urea with formaldehyde, said polyvinyl acetate having a saponification number between 10 and 300, the proportions of the polyvinyl acetate and the condensation product being within the limits of 25:75 and 75:25.

3. A sizing composition for water-insensitive yarns comprising a partially saponified polyvinyl acetate and a water-soluble condensation product of N-beta hydroxyethyl urea with formaldehyde, said polyvinyl acetate having a viscosity of 1.5 to 20 centipoises ma 4% water solution at 20 C., the proportions of the polyvinyl acetate and the condensation product being within the limits of 25:75 and 75:25. i

4. A sizing composition for-water-insensitive yarns comprising anaqueous solution containing a partially saponified polyvinyl acetate and a water-soluble condensation product of N-beta hydroxyethyl urea with formaldehyde, the proportions of the saponified polyvinyl acetate and the condensation product being within the limits of 25:75 and 75:25, and the total quantity of the partially saponified polyvinyl acetate and condensation product being from 5% to 15% of said composition, said polyvinyl acetate having a saponification number between and 300.

5. A slasher sizing composition for water-insensitive yarns comprising an aqueous solution containing equal parts by weight of a partially saponified polyvinyl acetate and the water-soluble condensation product of N-beta hydroxyethyl urea with formaldehyde, said polyvinyl acetate having a saponification number between 10 and 300.

6. A slasher sizing composition for water-insensitive yarns comprising an aqueous solution containing equal parts by weight of a partially saponified polyvinyl acetate and the water-soluble condensation product of N-beta hydroxyethyl urea with formaldehyde, said polyvinyl acetate having a saponification number of 140, the total quantity of said partially saponified polyvinyl acetate and condensation product consisting of 11.5% of the composition.

7. A yarn composed of a linear polyamide comprising the reaction product of a linear polymer- Iorming composition which comprises in substantial amount reacting material selected from at least one or the groups consisting of (a) monoaminomonocarboxylicacids and (b) mixtures of 6 diamine with dibasic carboxylic acid; said yarn having a coating of a size containing a hydroxylated polyvinyl resin and a water-soluble condensation product of N-beta hydroxyethyl urea with formaldehyde, the proportions of the hydroxylated polyvinyl resin and the condensation product being within the limits of 25:75 and 75:25, said polyvinyl resin having 1% to 50% of the carbon atoms in the polyvinyl chain attached to hydroxyl groups, thesize resulting from said composition being readily removable in an aqueous boil-oil bath.

8. A yarn composed of a linear polyamide com- I prising the reaction product of a linear polymerforming composition which comprises in substantial amount reacting material selected from at least one of the groups consisting of (a) monoaminomonocarboxylic acids and (b) mixtures of diamine with -dibasic carboxylic acid; said yarn having a coating of a size containing a partially saponified polyvinyl acetate and a water-soluble condensation product of N-beta hydroxyethyl urea with formaldehyde, the proportions of the partially saponified polyvinyl acetate and the condensation product being within the limits of 25:75 and :25, said partially saponiified polyvinyl acetate having a saponification number between 10 and 300.

9. A weaving yarn composed of a linear polyamide comprising the reaction product of a linear polymereforming composition which comprises in substantial amount reacting material. selected.

from at least one of the groups consisting of (a) monoaminomonocarboxylic acids'and (b) mixtures of diamine with dibasic carboxylic acid; s'aid yarn having a coating of a size containing equal parts by weight of a partially saponified polyvinyl acetate and a water-soluble condensation product of N-beta hydroxyethyl urea with formaldehyde, said partially saponified polyvinyl acetate having a saponification number between 10 and 300.

10. A weaving yarn composed of a linear polyamide comprising the reaction product of a linear polymer-forming composition which comprises in substantial amount reacting material selected from at least one of the groups consisting of (a) monoaminomonocarboxylic acids and (b) mixtures of diamine with dibasic carboxylic acid; said yarn having a coating of a size containing equal parts by weight of a partially saponified polyvinyl acetate and a water-soluble condensation product of N-.beta hydroxyethyl urea with formaldehyde, said partially saponified polyvinyl acetate having a saponification number of and a viscosity of 4 in a 4% water solution at 20 C.

VERNAL RICHARD HARDY. WALTER RICHARD HAEFELE. 

